CODEWITHSUNDEEP
javascripthtml
Bartek
Bartek

Reputation: 15

JavaScript countdown

Why wont it countdown?

<script language="JavaScript" TYPE="text/javascript">
var container = document.getElementById('dl');
var seconds = 10;
var timer;
function countdown() {
seconds--;
if(seconds > 0) {
    container.innerHTML = 'Please wait <b>'+seconds+'</b> seconds..';
} else {
    container.innerHTML = '<a href="download.php">Download</a>';
    clearInterval(timer);
}
}
timer = setInterval(countdown, 1000);
</script>

<div id="dl"></div>
<input type="button" onclick="setInterval(countdown, 1000);" id="dl" value="Download" />

Upvotes: 1

Views: 2414

Answers (3)

JoeNathan
JoeNathan

Reputation: 1

The setInterval takes a string to execute, not a function pointer.

timer = setInterval("countdown()", 1000);

Upvotes: -2

Guffa
Guffa

Reputation: 700800

Because you are trying to reach the element before it exists, as the code runs before the element is loaded.

Move the line that locates the element inside the function:

<script type="text/javascript">

var seconds = 10;
var timer;

function countdown() {
  var container = document.getElementById('dl');
  seconds--;
  if(seconds > 0) {
    container.innerHTML = 'Please wait <b>'+seconds+'</b> seconds..';
  } else {
    container.innerHTML = '<a href="download.php">Download</a>';
    clearInterval(timer);
  }
}

timer = setInterval(countdown, 1000);

</script>

<div id="dl"></div>
<input type="button" onclick="setInterval(countdown, 1000);" id="dl" value="Download" />

Upvotes: 1

Pascal MARTIN
Pascal MARTIN

Reputation: 401182

Try to move the <script> block after the <div id="dl"></div>.


This way, when document.getElementById('dl'); is executed, the corresponding element in the page will already exist.

With what you posted, when document.getElementById('dl'); is executed, the corresponding <div> is not there yet -- and, so, cannot be found.

Upvotes: 4

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